[PIG-454] group by followed by group ALL causes error in reduce

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.2.0
• Fix Version/s: 0.2.0
• Assignee: Alan Gates
• Reporter: Pradeep Kamath
• Created: 24/Sep/08 01:00
• Updated: 24/Mar/10 22:04
• Resolved: 25/Sep/08 16:21

Description

Script:

a = load 'st10k' as (name, age, gpa);
b = group a by name;
c = foreach b generate flatten(group), COUNT(a) as cnt;
d = group c all;
e = foreach d generate AVG(c.cnt);
dump e;

Error:

2008-09-23 17:58:12,002 [main] ERROR org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - Job failed!
2008-09-23 17:58:12,004 [main] ERROR org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.Launcher - Error message from task (map) tip_200809051428_0117_m_000000java.io.IOException: wrong key class: org.apache.pig.impl.io.NullableTuple is not class org.apache.pig.impl.io.NullableText
        at org.apache.hadoop.io.SequenceFile$Writer.append(SequenceFile.java:995)
        at org.apache.hadoop.mapred.MapTask$CombineOutputCollector.collect(MapTask.java:1079)
        at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigCombiner$Combine.reduce(PigCombiner.java:155)
        at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigCombiner$Combine.reduce(PigCombiner.java:56)
        at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.combineAndSpill(MapTask.java:872)
        at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.sortAndSpill(MapTask.java:779)
        at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.flush(MapTask.java:691)
        at org.apache.hadoop.mapred.MapTask.run(MapTask.java:220)
        at org.apache.hadoop.mapred.TaskTracker$Child.main(TaskTracker.java:2124)

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